feat: create a task model

migrations/2024-08-19-105140_create_tasks/up.sql

@@ -0,0 +1,11 @@
+-- Your SQL goes here
+
+CREATE TABLE "tasks"(
+	"id" SERIAL NOT NULL PRIMARY KEY,
+	"title" TEXT NOT NULL,
+	"deadline" DATE,
+	"category" JSONB NOT NULL,
+	"project_id" INT4,
+	FOREIGN KEY ("project_id") REFERENCES "projects"("id")
+);
+